Print this pageAnisotropic and Petrophysics of a Gas Reservoir in a Horizontal Well with a High Angle Pilot Well; Burgos Basin, México
The Burgos basin includes an area of 50,000 km2, in the northeast of the Mexican Republic, mainly the states of Tamaulipas and Nuevo Leon. In the last years the Burgos basin has become one of the most important dry gas producers of Mexico.
The present work shows two important concepts in the Gas reservoir description, Anisotropic and petrophysic properties; this study was done in a reservoir crossed by the well Bayo 35-H which is a horizontal well with a high angle pilot well the Bayo-35. The Bayo field is located in Burgos basin oriental area.
The study starts with the concern of the integration of conventional core data and special and conventional well logs; obtained in open hole, with the objective to calibrate, detail and analyze with better precision the anisotropic and petrophysical characteristics, also define the reservoirs potential qualitatively and quantitatively.
This reservoir has a net thickness between 25 and 70 meters, composed of siliciclastic sediments from the Eocene time period found in the Jackson Medium formation,. These sands show excellent porosity "ø" (between 14 and 35 %) and excellent permeability "k" (between 4 mDarcy to 3.5 Darcy) obtained from core data.
Anisotropic and petrophysics properties and types of rock are described in this paper, such as: anisotropic heterogeneity, index of reservoir quality, rock types, flow units, R35 and FZ1 (by means of Windland graphic and modified Lorenz), salinity (NaCl) and Rw electrical properties, and mineralogy of this producing sand. Has been based on the study of cores (conventional and sidewall cores), cross-plots, petrographic images and spectroscopy electronic microscan (SEM) and interpretation and evaluation of special logs.
This reservoir has produced gas and condensate, at a gas rate from 1 to 5 mmscf, the bottom hole flowing pressure is from 650 to 750 psi. Actual production history shows an accumulated production of 4 Bscf.
AAPG Search and Discover Article #90100©2009 AAPG International Conference and Exhibition 15-18 November 2009, Rio de Janeiro, Brazil